Missing Brain ‘Brake’ Could Be Source Of Phobias And Anxiety Disorders

A team led by researchers from the Medical University of Vienna has discovered one possible source of anxiety disorders and severe phobias – a missing inhibitory connection or “brake” in the brain.

When experienced at a manageable level, fear can make people alert and help protect them against danger, it can also disrupt an individual’s sensory perception and reduce happiness when it becomes disproportionate. Now the investigative team has found a possible trigger located in the amygdala and the orbitofrontal cortex in the frontal lobe, which together serve as a control center of sorts for emotional regulation.

In healthy subjects, they found that the circuit had “negative feedback” and “calmness” was identified. Functional magnetic resonance imaging (fMRI) scans on individuals with social phobias reportedly showed the opposite to be true for them. Those men and women possessed differences in an essential inhibitory connection which could help explain why they have such difficulty keeping their fears and anxieties in check.

Lead researcher Christian Windischberger and colleagues were also able to discover how the parts of the brain that are involved in processing emotions can influence one another. The study participants were shown a collection of “emotional faces” such as laughing, crying, happiness and anger while undergoing fMRI scans. As those expressions were being viewed, neuronal activity was triggered in the brain, the researchers explained.

While the test subjects looked no different from one another, the healthy ones were able to maintain their calmness despite the emotional nature of the images thanks to their mental “brake.” On the other hand, the brains of those who suffered from social phobias were deeply influenced by the images, as very strong neuronal activity was observed by Windischberger’s team.

“We have the opportunity not only to localize brain activity and compare it between groups, but we can now also make statements regarding functional connections within the brain,” said primary author Ronald Sladky. “In psychiatric conditions especially, we can assume that there are not complete failures of these connections going on, but rather imbalances in complex regulatory processes.”

The study, which appears in the latest edition of the journal Cerebral Cortex, will lead to an improved understanding of these neuronal mechanisms and might help medical experts develop new methods of treating anxiety disorders and phobias. The goal, the researchers said, is to better understand was impact drugs and psychotherapy will have on the networks involved so that people can get a better grasp on their fears.